Evolution and prognosis of tricuspid and mitral regurgitation following cardiac implantable electronic devices: a systematic review and meta-analysis.

AIMS: Significant changes in tricuspid regurgitation (TR) and mitral regurgitation (MR) post-cardiac implantable electronic devices (CIEDs) are increasingly recognized. However, uncertainty remains as to whether the risk of CIED-associated TR and MR differs with right ventricular pacing (RVP) via CIED with trans-tricuspid RV leads, compared with cardiac resynchronization therapy (CRT), conduction system pacing (CSP), and leadless pacing (LP). The study aims to synthesize extant data on risk and prognosis of significant post-CIED TR and MR across pacing strategies. METHODS AND RESULTS: We searched PubMed, EMBASE, and Cochrane Library databases published until 31 October 2023. Significant post-CIED TR and MR were defined as ≥ moderate. Fifty-seven TR studies (n = 13 723 patients) and 90 MR studies (n = 14 387 patients) were included. For all CIED, the risk of post-CIED TR increased [pooled odds ratio (OR) = 2.46 and 95% CI = 1.88-3.22], while the risk of post-CIED MR reduced (OR = 0.74, 95% CI = 0.58-0.94) after 12 and 6 months of median follow-up, respectively. Right ventricular pacing via CIED with trans-tricuspid RV leads was associated with increased risk of post-CIED TR (OR = 4.54, 95% CI = 3.14-6.57) and post-CIED MR (OR = 2.24, 95% CI = 1.18-4.26). Binarily, CSP did not alter TR risk (OR = 0.37, 95% CI = 0.13-1.02), but significantly reduced MR (OR = 0.15, 95% CI = 0.03-0.62). Cardiac resynchronization therapy did not significantly change TR risk (OR = 1.09, 95% CI = 0.55-2.17), but significantly reduced MR with prevalence pre-CRT of 43%, decreasing post-CRT to 22% (OR = 0.49, 95% CI = 0.40-0.61). There was no significant association of LP with post-CIED TR (OR = 1.15, 95% CI = 0.83-1.59) or MR (OR = 1.31, 95% CI = 0.72-2.39). Cardiac implantable electronic device-associated TR was independently predictive of all-cause mortality [pooled hazard ratio (HR) = 1.64, 95% CI = 1.40-1.90] after median of 53 months. Mitral regurgitation persisting post-CRT independently predicted all-cause mortality (HR = 2.00, 95% CI = 1.57-2.55) after 38 months. CONCLUSION: Our findings suggest that, when possible, adoption of pacing strategies that avoid isolated trans-tricuspid RV leads may be beneficial in preventing incident or deteriorating atrioventricular valvular regurgitation and might reduce mortality.

Atrial fibrillation and risk of adverse outcomes in heart failure with reduced, mildly reduced, and preserved ejection fraction: A systematic review and meta-analysis.

INTRODUCTION: Heart failure (HF) and atrial fibrillation (AF) frequently co-exist. Contemporary classification of HF categorizes it into HF with reduced ejection fraction (HFrEF), HF with mildly reduced ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF). Aggregate data comparing the risk profile of AF between these three HF categories are lacking. METHODS: We conducted a systematic review and meta-analysis aimed at determining any significant differences in AF-associated all-cause mortality, HF hospitalizations, cardiovascular mortality (CV), and stroke between HFrEF, HFmrEF, and HFpEF. A systematic search of PubMed, EMBASE, and Cochrane Library databases until February 28, 2023. Data were combined using DerSimonian-Laird random effects model. RESULTS: A total of 22 studies comprising 248 323 patients were retained: HFrEF 123 331 (49.7%), HFmrEF 40 995 (16.5%), and HFpEF 83 997 (33.8%). Pooled baseline AF prevalence was 36% total population, 30% HFrEF, 36% HFmrEF, and 42% HFpEF. AF was associated with a higher risk of all-cause mortality in the total population with pooled hazard ratio (HR) = 1.13 (95% confidence interval [CI] = 1.07-1.21), HFmrEF (HR = 1.25, 95% CI = 1.05-1.50) and HFpEF (HR = 1.16, 95% CI = 1.09-1.24), but not HFrEF (HR = 1.03, 95% CI = 0.93-1.14). AF was associated with a higher risk of HF hospitalizations in the total population (HR = 1.29, 95% CI = 1.14-1.46), HFmrEF (HR = 1.64, 95% CI = 1.20-2.24), and HFpEF (HR = 1.46, 95% CI = 1.17-1.83), but not HFrEF (HR = 1.01, 95% CI = 0.87-1.18). AF was only associated with CV in the HFpEF subcategory but was associated with stroke in all three HF subtypes. CONCLUSIONS: AF appears to be associated with a higher risk of all-cause mortality and HF hospitalization in HFmrEF and HFpEF. With these findings, the paucity of data and treatment guidelines on AF in the HFmrEF subgroup becomes even more significant and warrant further investigations.

Persistence of significant secondary mitral regurgitation post-cardiac resynchronization therapy and survival: a systematic review and meta-analysis : Mitral regurgitation and mortality post-CRT.

Cardiac resynchronization therapy (CRT) significantly reduces secondary mitral regurgitation (MR) in patients with severe left ventricular systolic dysfunction. However, uncertainty remains as to whether improvement in secondary MR correlates with improvement with mortality seen in CRT. We conducted a meta-analysis to determine the association of persistent unimproved significant secondary MR (defined as moderate or moderate-to-severe or severe MR) compared to improved MR (no MR or mild MR) post-CRT with all-cause mortality, cardiovascular mortality, and heart failure hospitalization. A systematic search of PubMed, EMBASE, and Cochrane Library databases till July 31, 2022 identified studies reporting clinical outcomes by post-CRT secondary MR status. In 12 prospective studies of 4954 patients (weighted mean age 66.8 years, men 77.8%), the median duration of follow-up post-CRT at which patients were re-evaluated for significant secondary MR was 6 months and showed significant relative risk reduction of 30% compared to pre-CRT. The median duration of follow-up post-CRT for ascertainment of main clinical outcomes was 38 months. The random effects pooled hazard ratio (95% confidence interval) of all-cause mortality in patients with unimproved secondary MR compared to improved secondary MR was 2.00 (1.57-2.55); p < 0.001). There was insufficient data to evaluate secondary outcomes in a meta-analysis, but limited data that examined the relationship showed significant association of unimproved secondary MR with increased cardiovascular mortality and heart failure hospitalization. The findings of this meta-analysis suggest that lack of improvement in secondary MR post-CRT is associated with significantly elevated risk of all-cause mortality and possibly cardiovascular mortality and heart failure hospitalization. Future studies may investigate approaches to address persistent secondary MR post-CRT to help improved outcome in this population.

Blood Pressure Variability and Risk of Atrial Fibrillation in Adults With Type 2 Diabetes.

BACKGROUND: There is a paucity of epidemiological data on the association between long-term variability of blood pressure (BP) and incident atrial fibrillation (AF). OBJECTIVES: The purpose of this study was to evaluate the association of BP variability with incident AF in a large sample of adults with type 2 diabetes. METHODS: We included participants who had ≥5 BP measurements in the first 24 months of action to control cardiovascular risk in diabetes. The visit-to-visit variability of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was estimated using the coefficient of variation, SD, and variability independent of the mean. Incident AF was recorded using follow-up electrocardiograms. Modified Poisson regression was used to generate risk ratios (RRs) and 95% CI for AF. RESULTS: A total of 8,399 participants were included (average age 62.6 ± 6.5 years, 38.8% women, 63.2% White). Over a median follow-up of 5 years, 155 developed AF. Compared to the lowest quartile, the highest quartile of BP variability was associated with an increased risk of AF (RR: 1.85 [95% CI: 1.13-3.03] and 1.63 [95% CI: 1.01-2.65] for coefficient of variation of SBP and DBP, respectively). Participants in the highest quartile of both SBP and DBP had a 2-fold higher risk of AF compared to those in the lowest 3 quartiles of both SBP and DBP (RR: 1.94; 95% CI: 1.29-2.93). CONCLUSIONS: In a large cohort of adults with type 2 diabetes, higher variability in SBP and DBP was independently associated with an increased risk of AF.

Cardiac autonomic dysfunction and risk of incident stroke among adults with type 2 diabetes.

Introduction: There is a dearth of data on the association between cardiac autonomic neuropathy (CAN) with incident stroke among individuals with diabetes mellitus. We evaluated this association in a large sample of adults with type 2 diabetes. Patients and methods: Participants with type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study without atherosclerotic cardiovascular disease at baseline were included. CAN was assessed at baseline by heart rate variability (HRV) indices and QT index (QTI) calculated from 10-s resting electrocardiograms. HRV was assessed using standard deviation of all normal-to-normal R-Rs intervals (SDNN) and root mean square of successive differences between normal-to-normal R-R intervals (rMSSD). CAN was defined based on several composite measures of SDNN, QTI, resting heart rate and peripheral neuropathy. We used Cox proportional hazards regression to generate hazard ratios (HR) and 95% confidence intervals (CI) for incident stroke in relation to CAN. Results: A total of 3493 participants (mean age 62.2 years, 44.5% women, 62.9% White) were included. Over a median follow-up of 5.0 years, 50 stroke cases occurred (incidence rate 3.0/1000 person-years [95% CI 2.2-3.9]). After adjusting for confounders, low HRV was associated with a higher risk of stroke (HR of 2.20 [95% CI 1.23-3.93] and 1.88 [95% CI 1.04-3.41] for low SDNN and rMSSD, respectively). Participants with CAN (defined as lowest quartile of SDNN and highest quartiles of QTI and heart rate) had a 5.7-fold greater risk of stroke (HR 5.70, 95% CI 2.49-13.08). Discussion and conclusion: CAN was independently associated with an increased risk of incident stroke in a large cohort of adults with type 2 diabetes.

Are arrhythmias the drivers of sudden cardiac death in heart failure with preserved ejection fraction? A review.

In patients with heart failure with preserved ejection fraction (HFpEF), sudden cardiac death (SCD) accounts for approximately 25-30% of all-cause mortality and 40% of cardiovascular mortality in properly adjudicated large clinical trials. The mechanism of SCD in HFpEF remains unknown but thought to be driven by arrhythmic events. Apart from atrial fibrillation, which is prevalent in approximately 45% of HFpEF patients, the true burden of other cardiac arrhythmias in HFpEF remains undetermined. The incidence and risk of clinically significant advanced cardiac conduction disease with bradyarrhythmias and ventricular arrhythmias remain less known. Recommendations have been made for long-term cardiac rhythm monitoring to determine the incidence of arrhythmias and clarify mechanisms and mode of death in HFpEF patients. In animal studies, spontaneous ventricular arrhythmias and SCD are significantly elevated in HFpEF animals compared with controls without heart failure. In humans, these studies are scant, with a few published small-size studies suggesting an increased incidence of ventricular arrhythmias in HFpEF. Higher rates of clinically significant conduction disease and cardiac pacing are seen in HFpEF compared with the general population. Excepting atrial fibrillation, the predictive effect of other arrhythmias on heart failure hospitalization, all-cause mortality, and precisely SCD remains unknown. Given the high occurrence of SCD in the HFpEF population, it could potentially become a target for therapeutic interventions if driven by arrhythmias. Studies to address these knowledge gaps are urgently warranted. In this review, we have summarized data on arrhythmias and SCD in HFpEF while highlighting avenues for future research in this area.

Autonomic dysfunction and risk of severe hypoglycemia among individuals with type 2 diabetes.

There are limited data on the link between cardiac autonomic neuropathy (CAN) and severe hypoglycemia in type 2 diabetes. Here, we evaluated the associations of CAN with severe hypoglycemia among 7,421 adults with type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes study. CAN was defined using ECG-derived measures. Cox's and Andersen-Gill regression models were used to generate HRs (HRs) for the first and recurrent severe hypoglycemic episodes, respectively. Over 4.7 years, there were 558 first and 811 recurrent hypoglycemic events. Participants with CAN had increased risks of a first episode or recurrent episodes of severe hypoglycemia. The intensity of glycemic management modified the CAN association with hypoglycemia. In the standard glycemic management group, compared with those of participants without CAN, HRs for a first severe hypoglycemia event and recurrent hypoglycemia were 1.58 and 1.96, respectively. In the intensive glycemic management group, HRs for a first severe hypoglycemia event and recurrent hypoglycemia were 1.10 and 1.24, respectively. In summary, CAN was independently associated with higher risks of a first hypoglycemia event and recurrent hypoglycemia among adults with type 2 diabetes, with the highest risk observed among those on standard glycemic management.

Association of heart rate variability with progression of retinopathy among adults with type 2 diabetes.

AIM: We evaluated the associations of heart rate variability (HRV) with incident vision-threatening retinopathy and retinopathy progression among adults with type 2 diabetes. METHODS: Participants recruited to the ACCORD (Action to Control Cardiovascular Risk in Diabetes) study with HRV measures at baseline were analysed. HRV measures included standard deviation of all normal-to-normal intervals (SDNN) and root mean square of successive differences between normal-to-normal intervals (rMSSD). Low SDNN was defined as SDNN <8.2 ms; low rMSSD as rMSSD <8.0 ms. We used multivariable adjusted Cox proportional hazards and modified Poisson regression models to generate risk estimates for incident vision-threatening retinopathy and retinopathy progression, respectively. RESULTS: A total of 5810 participants without incident vision-threatening retinopathy at baseline (mean age 62 years, 40.5% women, 63.5% White) were included. Over a median of 4.7 years, 280 incident vision-threatening retinopathy cases requiring treatment occurred. Low HRV (vs. normal HRV) was associated with higher risk of incident vision-threatening retinopathy (adjusted hazard ratio 1.32 [95%CI 1.03-1.71] and 1.14 [95%CI 1.01-1.28] for low SDNN and rMSSD, respectively). In the subset of 2184 participants with complete eye examinations at baseline and 4 years, 191 experienced retinopathy progression, and low HRV (vs. normal HRV) was associated with a higher risk of retinopathy progression (adjusted relative risks 1.36 [95%CI 1.01-1.83] and 1.36 [95%CI 1.01-1.84] for low SDNN and rMSSD, respectively). CONCLUSIONS: Cardiac autonomic neuropathy, as assessed by low HRV, was independently associated with increased risks of incident vision-threatening retinopathy and overall retinopathy progression in a large cohort of adults with type 2 diabetes.

Burden of Microvascular Disease and Risk of Atrial Fibrillation in Adults with Type 2 Diabetes.

BACKGROUND: Epidemiological data on the associations of microvascular disease with atrial fibrillation are scarce. We evaluated the associations of diabetes-related microvascular disease in multiple vascular beds and its burden with incident atrial fibrillation among adults with type 2 diabetes. METHODS: A total of 7603 participants with type 2 diabetes and without atrial fibrillation were assessed for diabetic kidney disease, retinopathy, or neuropathy at baseline in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. Incident atrial fibrillation events were adjudicated using follow-up electrocardiograms. Modified Poisson regression was used to generate risk ratios (RRs) and 95% confidence intervals (CIs) for atrial fibrillation. RESULTS: Of the 7603 participants (mean age 62.5 years, 38.0% women, 63.4% white), 63.3% (n = 4816) had microvascular disease-defined as the presence of ≥1 of: diabetic kidney disease, retinopathy, or neuropathy at baseline. Over a median of 7 years, there were 137 atrial fibrillation events (1.8%). Participants with microvascular disease had a 1.9-fold higher risk of incident atrial fibrillation compared with those without microvascular disease (RR 1.88; 95% CI, 1.20-2.95). Compared with no microvascular disease, the RRs for atrial fibrillation were 1.62 (95% CI, 1.01-2.61) and 2.47 (95% CI, 1.46-4.16) for those with 1 and ≥2 microvascular territories affected, respectively. The RRs for atrial fibrillation by type of microvascular disease were 1.57 (95% CI, 1.09-2.26), 0.95 (95% CI, 0.53-1.70), and 1.67 (95% CI, 1.15-2.44) for neuropathy, retinopathy, and diabetic kidney disease, respectively. CONCLUSIONS: In a large cohort of adults with type 2 diabetes, the presence of microvascular disease and its burden were independently associated with higher risk of incident atrial fibrillation.

Severe Hypoglycemia and Incidence of QT Interval Prolongation Among Adults With Type 2 Diabetes.

CONTEXT: There is a paucity of large-scale epidemiological studies on the link between severe hypoglycemia (SH) and corrected QT (QTc) interval prolongation in type 2 diabetes (T2DM). OBJECTIVE: To evaluate the association of SH with QTc prolongation in adults with T2DM. METHODS: Prospective cohort analysis of participants enrolled in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) study without QTc prolongation at baseline. SH was assessed over a 24-month period. Incident QTc prolongation was ascertained using follow-up electrocardiograms. Modified Poisson regression was used to generate the risk ratio (RR) and 95% CI for QTc prolongation. RESULTS: Among 8277 participants (mean age 62.6 years [SD 6.5], 38.7% women, 62.8% White), 324 had ≥1 SH episode (3.9%). Over a median of 5 years, 517 individuals developed QTc prolongation (6.3%). Participants with SH had a 66% higher risk of QTc prolongation (RR 1.66, 95% CI 1.16-2.38). The incidence of QTc prolongation was 10.3% (27/261) and 14.3% (9/63) for participants with 1 and ≥2 SH, respectively. Compared with no SH, RRs for patients with 1 and ≥2 SH episodes were 1.57 (95% CI 1.04-2.39) and 2.01 (95% CI 1.07-3.78), respectively. Age modified the association of SH with QTc prolongation (PInteraction = .008). The association remained significant among younger participants (<61.9 years [median age]: RR 2.63, 95% CI 1.49-4.64), but was nonsignificant among older participants (≥61.9 years: RR 1.37, 95% CI 0.87-2.17). CONCLUSION: In a large population with T2DM, SH was associated with an increased risk of QTc prolongation independently of other risk factors such as cardiac autonomic neuropathy. The association was strongest among younger participants.

Cardiac autonomic neuropathy and risk of incident heart failure among adults with type 2 diabetes.

AIMS: Community-based data on the association between cardiac autonomic neuropathy (CAN) and incident heart failure (HF) in type 2 diabetes are limited. We evaluated the association of CAN with incident HF in adults with type 2 diabetes. METHODS AND RESULTS: This analysis included participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study without HF at baseline. CAN was assessed by electrocardiogram-based measures of heart rate variability (HRV) and QT interval index (QTI). HRV was measured using standard deviation of all normal-to-normal intervals (SDNN) and root mean square of successive differences between normal-to-normal intervals (rMSSD). CAN was defined using composite measures of the lowest quartile of SDNN and highest quartiles of QTI and heart rate. Multivariable Cox regression models were used to generate adjusted hazard ratios (aHR) for HF in relation to various CAN measures. A total of 7160 participants (mean age 62.3 [standard deviation 6.4] years, 40.8% women, 61.9% white) were included. Over a median follow-up of 4.9 years (interquartile range 4.0-5.7), 222 participants developed incident HF. After multivariable adjustment for relevant confounders, lower HRV as assessed by SDNN was associated with a higher risk of HF (aHR for the lowest vs highest quartile of SDNN: 1.70, 95% confidence interval [CI] 1.14-2.54). Participants with CAN (defined as lowest quartile of SDNN and highest quartiles of QTI and heart rate) had a 2.7-fold greater risk of HF (aHR 2.65, 95% CI 1.57-4.48). CONCLUSIONS: In a large cohort of adults with type 2 diabetes, CAN was independently associated with higher risk of incident HF.

Ventricular repolarization heterogeneity in patients with COVID-19: Original data, systematic review, and meta-analysis.

BACKGROUND: Coronavirus disease-2019 (COVID-19) has been associated with an increased risk of acute cardiac events. However, the effect of COVID-19 on repolarization heterogeneity is not yet established. In this study, we evaluated electrocardiogram (ECG) markers of repolarization heterogeneity in patients hospitalized with COVID-19. In addition, we performed a systematic review and meta-analysis of the published studies. METHODS: QT dispersion (QTd), the interval between T wave peak to T wave end (TpTe), TpTe/QT (with and without correction), QRS width, and the index of cardio-electrophysiological balance (iCEB) were calculated in 101 hospitalized COVID-19 patients and it was compared with 101 non-COVID-19 matched controls. A systematic review was performed in four databases and meta-analysis was conducted using Stata software. RESULTS: Tp-Te, TpTe/QT, QRS width, and iCEB were significantly increased in COVID-19 patients compared with controls (TpTe = 82.89 vs. 75.33 ms (ms), p-value = .005; TpTe/QT = 0.217 vs. 0.203 ms, p-value = .026). After a meta-analysis of 679 COVID-19 cases and 526 controls from 9 studies, TpTe interval, TpTe/QT, and TpTe/QTc ratios were significantly increased in COVID-19 patients. Meta-regression analysis moderated by age, gender, diabetes mellitus, hypertension, and smoking reduced the heterogeneity. QTd showed no significant correlation with COVID-19. CONCLUSION: COVID-19 adversely influences the ECG markers of transmural heterogeneity of repolarization. Studies evaluating the predictive value of these ECG markers are warranted to determine their clinical utility.

Coronary Artery Calcification and Plaque Characteristics in People Living With HIV: A Systematic Review and Meta-Analysis.

Background Studies have reported that people living with HIV have higher burden of subclinical cardiovascular disease, but the data are not adequately synthesized. We performed meta-analyses of studies of coronary artery calcium and coronary plaque in people living with HIV. Methods and Results We performed systematic search in electronic databases, and data were abstracted in standardized forms. Study-specific estimates were pooled using meta-analysis. 43 reports representing 27 unique studies and involving 10 867 participants (6699 HIV positive, 4168 HIV negative, mean age 52 years, 86% men, 32% Black) were included. The HIV-positive participants were younger (mean age 49 versus 57 years) and had lower Framingham Risk Score (mean score 6 versus 18) compared with the HIV-negative participants. The pooled estimate of percentage with coronary artery calcium >0 was 45% (95% CI, 43%-47%) for HIV-positive participants, and 52% (50%-53%) for HIV-negative participants. This difference was no longer significant after adjusting for difference in Framingham Risk Score between the 2 groups. The odds ratio of coronary artery calcium progression for HIV-positive versus -negative participants was 1.64 (95% CI, 0.91-2.37). The pooled estimate for prevalence of noncalcified plaque was 49% (95% CI, 47%-52%) versus 20% (95% CI, 17%-23%) for HIV-positive versus HIV-negative participants, respectively. Odds ratio for noncalcified plaque for HIV-positive versus -negative participants was 1.23 (95% CI, 1.08-1.38). There was significant heterogeneity that was only partially explained by available study-level characteristics. Conclusions People living with HIV have higher prevalence of noncalcified coronary plaques and similar prevalence of coronary artery calcium, compared with HIV-negative individuals. Future studies on coronary artery calcium and plaque progression can further elucidate subclinical atherosclerosis in people living with HIV.

Ongoing Risk of Ventricular Arrhythmias and All-Cause Mortality at Implantable Cardioverter Defibrillator Generator Change: A Systematic Review and Meta-Analysis.

[Figure: see text].

Risk of ventricular arrhythmia in cardiac resynchronization therapy responders and super-responders: a systematic review and meta-analysis.

AIMS: Response to cardiac resynchronization therapy (CRT) is associated with improved survival, and reduction in heart failure hospitalization, and ventricular arrhythmia (VA) risk. However, the impact of CRT super-response [CRT-SR, increase in left ventricular ejection fraction (LVEF) to ≥ 50%] on VA remains unclear. METHODS AND RESULTS: We undertook a meta-analysis aimed at determining the impact of CRT response and CRT-SR on risk of VA and all-cause mortality. Systematic search of PubMed, EMBASE, and Cochrane databases, identifying all relevant English articles published until 31 December 2019. A total of 34 studies (7605 patients for VA and 5874 patients for all-cause mortality) were retained for the meta-analysis. The pooled cumulative incidence of appropriate implantable cardioverter-defibrillator therapy for VA was significantly lower at 13.0% (4.5% per annum) in CRT-responders, vs. 29.0% (annualized rate of 10.0%) in CRT non-responders, relative risk (RR) 0.47 [95% confidence interval (CI) 0.39-0.56, P < 0.0001]; all-cause mortality 3.5% vs. 9.1% per annum, RR of 0.38 (95% CI 0.30-0.49, P < 0.0001). The pooled incidence of VA was significantly lower in CRT-SR compared with CRT non-super-responders (non-responders + responders) at 0.9% vs. 3.8% per annum, respectively, RR 0.22 (95% CI 0.12-0.40, P < 0.0001); as well as all-cause mortality at 2.0% vs. 4.3%, respectively, RR 0.47 (95% CI 0.33-0.66, P < 0.0001). CONCLUSIONS: Cardiac resynchronization therapy super-responders have low absolute risk of VA and all-cause mortality. However, there remains a non-trivial residual absolute risk of these adverse outcomes in CRT responders. These findings suggest that among CRT responders, there may be a continued clinical benefit of defibrillators.

A Systematic Review of the Spectrum of Cardiac Arrhythmias in Sub-Saharan Africa.

Major structural cardiovascular diseases are associated with cardiac arrhythmias, but their full spectrum remains unknown in sub-Saharan Africa (SSA), which we addressed in this systematic review. Atrial fibrillation/atrial flutter (AF/AFL) prevalence is 16-22% in heart failure, 10-28% in rheumatic heart disease, 3-7% in cardiology admissions, but <1% in the general population. Use of oral anticoagulation is heterogenous (9-79%) across SSA. The epidemiology of sudden cardiac arrest/death is less characterized in SSA. Cardiopulmonary resuscitation is challenging, owing to low awareness and lack of equipment for life-support. About 18% of SSA countries have no cardiac implantable electronic devices services, leaving hundreds of millions of people without any access to treatment for advanced bradyarrhythmias, and implant rates are more than 200-fold lower than in the western world. Management of tachyarrhythmias is largely non-invasive (about 80% AF/AFL via rate-controlled strategy only), as electrophysiological study and catheter ablation centers are almost non-existent in most countries. Highlights: - Atrial fibrillation/flutter prevalence is 16-22% in heart failure, 10-28% in rheumatic heart disease, 3-7% in cardiology admissions, and <1% in the general population in sub-Saharan Africa (SSA).- Rates of oral anticoagulation use for CHA2DS2VASC score ≥2 are very diverse (9-79%) across SSA countries.- Data on sudden cardiac arrest are scant in SSA with low cardiopulmonary resuscitation awareness.- Low rates of cardiac implantable electronic devices insertions and rarity of invasive arrhythmia treatment centers are seen in SSA, relative to the high-income countries.

Incidence of recreational sports-related sudden cardiac arrest in participants over age 12 in a general African population.

BACKGROUND: The incidence of sports-related sudden cardiac arrest (SrSCA) in sub-Saharan Africa is unknown. OBJECTIVE: To determine the incidence of sudden cardiac arrest (SCA) in non-competitive athletes in an urban population of Cameroon, a country in sub-Saharan Africa. METHODS: Two study populations in Cameroon were used. A 12-month, multisource surveillance system of 86 189 inhabitants over 12 years old recorded all deaths in two administrative districts of Douala City. All fields of sports, emergency medical service, local medical examiners and district hospital mortuaries were surveyed. Two blinded cardiologists used a verbal autopsy protocol to determine the cause of death. SCA was identified for all deaths occurring within 1 hour of onset of symptoms. A cross-sectional study was conducted among 793 persons in Yaoundé City, which is the second study population aimed at determining the proportion of people who are physically active. RESULTS: The mean age in the cross-sectional study was 27.3±10.7, with more men (56.2%). The cross-sectional study showed that 69.0% (95% CI 65.8 to 72.2) of the population could be considered to have at least 3 hours of physical activity per week. The surveillance found that among 288 all-cause deaths, 27 (9.4%) were due to SCA. One SrSCA was registered in a 35-year-old woman while running. Merging both sources revealed an SrSCA incidence of 1.7 (95% CI 0.2 to 12.0) cases per 100 000 athletes per year. CONCLUSION: This pioneer study reports the incidence estimates of SrSCA in a sub-Saharan African general population and should be regarded as a first step to a big problem.

Cardiac Pacing Training in Africa: Endorsed by the Africa Heart Rhythm Association (AFHRA): JACC International.

The field of pacing in Africa has evolved in an uncoordinated way across the continent with significant variation in local expertise, cost, and utilization. There are many countries where pacemaker services do not meet one-hundredth of the national demand. Regional, national, and institutional standards for pacemaker qualification and credentials are lacking. This paper reviews the current needs for bradycardia pacing and evaluates what standards should be set to develop pacemaker services in a resource-constrained continent, including the challenges and opportunities of capacity building and training as well as standards for training programs (training prerequisites, case volumes, program content, and evaluation).

Cardiac arrhythmia services in Africa from 2011 to 2018: the second report from the Pan African Society of Cardiology working group on cardiac arrhythmias and pacing.

AIMS: Cardiac arrhythmia services are a neglected field of cardiology in Africa. To provide comprehensive contemporary information on the access and use of cardiac arrhythmia services in Africa. METHODS AND RESULTS: Data on human resources, drug availability, cardiac implantable electronic devices (CIED), and ablation procedures were sought from member countries of Pan African Society of Cardiology. Data were received from 23 out of 31 countries. In most countries, healthcare services are primarily supported by household incomes. Vitamin K antagonists (VKAs), digoxin, and amiodarone were available in all countries, while the availability of other drugs varied widely. Non-VKA oral anticoagulants (NOACs) were unequally present in the African markets, while International Normalized Ratio monitoring was challenging. Four countries (18%) did not provide pacemaker implantations while, where available, the implantation and operator rates were 2.79 and 0.772 per million population, respectively. The countries with the highest pacemaker implantation rate/million population in descending order were Tunisia, Mauritius, South Africa, Algeria, and Morocco. Implantable cardioverter-defibrillator and cardiac resynchronization therapy (CRT) were performed in 15 (65%) and 12 (52%) countries, respectively. Reconditioned CIED were used in 5 (22%) countries. Electrophysiology was performed in 8 (35%) countries, but complex ablations only in countries from the Maghreb and South Africa. Marked variation in costs of CIED that severely mismatched the gross domestic product per capita was observed in Africa. From the first report, three countries have started performing simple ablations. CONCLUSION: The access to arrhythmia treatments varied widely in Africa where hundreds of millions of people remain at risk of dying from heart block. Increased economic and human resources as well as infrastructures are the critical targets for improving arrhythmia services in Africa.